The Pendle witch trials of 1612 are among the best-documented in English history, and have inspired writers and poets since the 19th century. Now Jeanette Winterson has added her own interpretation of the events, in a novella (for the newly revived Hammer Books imprint) that mixes a sharp-eyed view of history with elements of magic and some of the more outre touches that horror fans might expect.

In the wild country of Lancashire, Catholicism clung on as stubbornly as more ancient beliefs, and to King James I, the one was as dangerous as the other. Priests and witches were pursued with equal relish, neighbour often denouncing neighbour as one or the other before the light of suspicion fell on them. The Pendle trials resulted in the execution of nine women and two men, for the most part poor and uneducated, except for the gentlewoman Alice Nutter, whose inclusion among the group accused of celebrating a witches' Sabbat on Good Friday remains a mystery. Winterson's cast share the names of the historical protagonists, though she has reshaped them into fictional characters – even Shakespeare is given a cameo. Her Alice Nutter is a self-made woman, a widow grown rich from an invention born of her knowledge of alchemy, which she learned many years earlier from Dr John Dee, Queen Elizabeth's astrologer and magician. She is also a woman with a mysterious past, torn between her love for a woman, Elizabeth, whose dabbling in magic crossed a point of no return, and a secret priest tortured for his faith.

In spare, precise prose, Winterson conjures a world of casual brutality, where the poor live little better than animals and where justice is an unimaginable luxury. Women are raped because they have no voice to protest, children are sold, accusations fly between rival families until everyone is tainted by the stench of witchcraft. "Such women are poor," Alice Nutter tells the investigating magistrate Roger Nowell. "They are ignorant. They have no power in your world, so they must get what power they can in theirs. I have sympathy for them."

Naturally, it is this sympathy that proves Alice's downfall. Winterson is at her best here when she is dealing with real horrors, whether the disease and depredations of poverty and prison or the ingenious ways that men have devised to torture one another. The landscape she describes is bleak and atmospheric, inviting an affinity with dark powers. But the social realism sits uneasily alongside the supernatural elements: a severed head that speaks, or the appearances of the mysterious Dark Gentleman, to whom Alice is supposed to be a sacrifice. The story is at its least convincing in these moments, as if the truth of why women were accused of witchcraft – because they did not conform to convention – can't be reconciled with the demands of the horror genre. The description of a prisoner being skinned alive has a far more chilling effect here than the appearance of an animated corpse, because it is true.

Ultimately, this is a story about the relationship between power and fear, about the ways in which the strong must crush those whose potential powers unsettle or threaten their authority. But it is also a story in which love proves stronger than death. Like all horror stories, it asks the reader to suspend disbelief and enter into its parameters, but it can't shake off the truth that the real forces of darkness and light exist within the extremes of human nature.